Sketches often lead to distorted 3D models in AI modeling because AI struggles with ambiguous 2D cues (like inconsistent lines or incomplete shapes) or lacks training data matching the sketch’s style/context.
Sketches rely on implicit depth and proportion clues—AI may misinterpret these, such as a wobbly line being read as a curved surface instead of a straight edge. Limited training on similar sketches also causes the AI to fill gaps incorrectly.
To fix distortion, add simple depth cues (e.g., light cross-hatching for shadows) or use AI tools trained on your sketch style—this helps the model understand your intent without extra effort.